Rare-earth oxide based monolithic chamber material

ABSTRACT

A solid sintered ceramic article may include a solid solution comprising Y 2 O 3  at a concentration of approximately 30 molar % to approximately 60 molar %, Er 2 O 3  at a concentration of approximately 20 molar % to approximately 60 molar %, and at least one of ZrO 2 , Gd 2 O 3  or SiO 2  at a concentration of approximately 0 molar % to approximately 30 molar %. Alternatively, the solid sintered ceramic article a solid solution comprising 40-100 mol % of Y 2 O 3 , 0-50 mol % of ZrO 2 , and 0-40 mol % of Al 2 O 3 .

RELATED APPLICATIONS

This patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/903,215, filed Nov. 12, 2013.

TECHNICAL FIELD

Embodiments of the present invention relate, in general, to plasma resistant rare-earth oxide materials, and in particular to solid sintered ceramic articles formed from the plasma resistant rare-earth oxide materials.

BACKGROUND

In the semiconductor industry, devices are fabricated by a number of manufacturing processes producing structures of an ever-decreasing size. Some manufacturing processes such as plasma etch and plasma clean processes expose a substrate to a high-speed stream of plasma to etch or clean the substrate. The plasma may be highly corrosive, and may corrode processing chambers and other surfaces that are exposed to the plasma. This corrosion may generate particles, which frequently contaminate the substrate that is being processed, contributing to device defects. Additionally, the corrosion may cause metal atoms from chamber components to contaminate processed substrates (e.g., processed wafers).

As device geometries shrink, susceptibility to defects and metal contamination increases, and particle contaminant specifications and metal contaminant specifications become more stringent. Accordingly, as device geometries shrink, allowable levels of particle defects and metal contamination may be reduced. To minimize particle defects and metal contamination introduced by plasma etch and/or plasma clean processes, chamber materials have been developed that are resistant to plasmas. Examples of such plasma resistant materials include ceramics composed to Al₂O₃, MN, SiC and Y₂O₃. However, the plasma resistance properties of these ceramic materials may be insufficient for some applications. For example, plasma resistant ceramic lids and/or nozzles that are manufactured using traditional ceramic manufacturing processes may produce unacceptable levels of particle defects when used in plasma etch processes of semiconductor devices with critical dimensions of 90 nm or lower.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

FIG. 1 is a sectional view of a semiconductor processing chamber having one or more chamber components that are solid sintered ceramic articles created using ceramic materials provided in embodiments herein.

FIG. 2 illustrates a process for forming a solid sintered ceramic article, in accordance with one embodiment of the present invention.

FIG. 3 shows sputter resistance of various solid sintered ceramic articles to a plasma generated under a bias power of 2200 Watts, in accordance with embodiments of the present invention.

FIG. 4 shows erosion resistance of various solid sintered ceramic articles to a plasma generated using an N₂/H₂ chemistry, in accordance with embodiments of the present invention.

FIG. 5 shows erosion resistance of various solid sintered ceramic articles to a plasma generated using a CHF₄/CF₄ chemistry, in accordance with embodiments of the present invention.

FIG. 6A is a chart showing erosion resistance of various solid sintered ceramic articles to a plasma generated using an N₂/H₂ chemistry, in accordance with embodiments of the present invention.

FIG. 6B is a chart showing pre-etch and post-etch roughness for various bulk sintered ceramic articles.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention are directed to new sintered ceramic materials and to methods of manufacturing these new sintered ceramic materials. In embodiments, the sintered ceramic materials may have a solid solution that includes Y₂O₃ at a concentration of approximately 30 molar % to approximately 60 molar %, Er₂O₃ at a concentration of approximately 20 molar % to approximately 60 molar %, and at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 0 molar % to approximately 30 molar %. In other embodiments, the sintered ceramic materials may have a solid solution that includes a mixture of Y₂O₃, ZrO₂, and/or Al₂O₃. The new sintered ceramic materials may be used to create chamber components for a plasma etch reactor. Use of chamber components created with the new sintered ceramic materials described herein in a plasma etch reactor may cause on wafer metal contamination and/or particle defects to be greatly reduced as compared to use of chamber components created with conventional plasma resistant ceramic materials. In particular, metal contamination of yttrium, aluminum and zinc may be greatly reduced by use of the ceramic materials described in embodiments herein. Reduction of these metal contaminants on processed wafers may be dictated by manufacturers of semiconductors, displays, photovoltaics, micro-electro-mechanical systems (MEMS)) devices and so forth.

When the terms “about” and “approximate” are used herein, this is intended to mean that the nominal value presented is precise within ±10%.

Embodiments are described with reference to solid sintered ceramic articles that are chamber components for a plasma etch reactor (also referred to as a plasma etcher). For example, the ceramic articles may be process kit rings, chamber lid, gas distribution plates, shower heads, electrostatic chucks, and lift pins. However, the solid sintered ceramic materials described herein may also be used for other devices having components that are exposed to a plasma environment, such as a plasma cleaner, a plasma propulsion system, and so forth. Moreover, embodiments are described with reference to solid sintered ceramic articles. However, discussed embodiments also apply to deposited ceramic coatings, such as plasma sprayed ceramic coatings and ceramic coatings applied using ion assisted deposition (IAD) techniques. Accordingly, it should be understood that discussion of solid sintered ceramic materials also applies to deposited ceramic materials of the same compositions.

Embodiments are described herein with reference to ceramic articles that cause reduced particle defects and metal contamination when used in a process chamber for plasma etch and/or plasma clean processes. However, it should be understood that the ceramic articles discussed herein may also provide reduced particle defects and metal contamination when used in process chambers for other processes such as plasma enhanced chemical vapor deposition (PECVD), plasma enhanced physical vapor deposition (PEPVD), plasma enhanced atomic layer deposition (PEALD), and so forth, and non-plasma etchers, non-plasma cleaners, chemical vapor deposition (CVD) furnaces, physical vapor deposition (PVD) furnaces, and so forth.

FIG. 1 is a sectional view of a semiconductor processing chamber 100 having one or more chamber components that are solid sintered ceramic articles created using ceramic materials provided in embodiments herein. The processing chamber 100 may be used for processes in which a corrosive plasma environment is provided. For example, the processing chamber 100 may be a chamber for a plasma etch reactor (also known as a plasma etcher), a plasma cleaner, and so forth. Examples of chamber components that may be composed of or include a solid sintered plasma resistant ceramic material include an electrostatic chuck (ESC) 150, a ring (e.g., a process kit ring or single ring), a chamber wall, a gas distribution plate, a showerhead, a liner, a liner kit, a chamber lid 104, a nozzle 132, and so on. The solid sintered ceramic material used to form one or more of these chamber components is described in more detail below with reference to FIG. 2.

In one embodiment, the processing chamber 100 includes a chamber body 102 and a lid 130 that enclose an interior volume 106. The lid 130 may have a hole in its center, and the nozzle 132 may be inserted into the hole. In some embodiments, a showerhead is used instead of the lid 130 and nozzle 132. The chamber body 102 may be fabricated from aluminum, stainless steel or other suitable material. The chamber body 102 generally includes sidewalls 108 and a bottom 110. Any of the lid 130, nozzle 132, showerhead, and so on may include the solid sintered ceramic material.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protect the chamber body 102. Outer liner 116 can be a plasma resistant layer made from rare earth oxide based materials.

An exhaust port 126 may be defined in the chamber body 102, and may couple the interior volume 106 to a pump system 128. The pump system 128 may include one or more pumps and throttle valves utilized to evacuate and regulate the pressure of the interior volume 106 of the processing chamber 100.

The lid 130 may be supported on the sidewall 108 of the chamber body 102. The lid 130 may be opened to allow access to the interior volume 106 of the processing chamber 100, and may provide a seal for the processing chamber 100 while closed. A gas panel 158 may be coupled to the processing chamber 100 to provide process and/or cleaning gases to the interior volume 106 through the nozzle 132.

Examples of processing gases that may be used to process substrates in the processing chamber 100 include halogen-containing gases, such as C₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃ and SiF₄, among others, and other gases such as O₂, or N₂O. Examples of carrier gases include N₂, He, Ar, and other gases inert to process gases (e.g., non-reactive gases). A substrate support assembly 148 is disposed in the interior volume 106 of the processing chamber 100 below the lid 130. The substrate support assembly 148 holds the substrate 144 during processing. A ring 147 (e.g., a single ring) may cover a portion of the electrostatic chuck 150, and may protect the covered portion from exposure to plasma during processing. The ring 147 may be formed of any of the solid sintered ceramic materials described herein.

An inner liner 118 may be formed on the periphery of the substrate support assembly 148. The inner liner 118 may be a halogen-containing gas resistant material such as those discussed with reference to the outer liner 116.

In one embodiment, the substrate support assembly 148 includes a mounting plate 162 supporting a pedestal 152, and an electrostatic chuck 150. The electrostatic chuck 150 further includes a thermally conductive base 164 and an electrostatic puck 166 bonded to the thermally conductive base by a bond 138, which may be a silicone bond in one embodiment. The mounting plate 162 is coupled to the bottom 110 of the chamber body 102 and includes passages for routing utilities (e.g., fluids, power lines, sensor leads, etc.) to the thermally conductive base 164 and the electrostatic puck 166.

The thermally conductive base 164 and/or electrostatic puck 166 may include one or more optional embedded heating elements 176, embedded thermal isolator 174 and/or conduits 168, 170 to control a lateral temperature profile of the substrate support assembly 148. The conduits 168, 170 may be fluidly coupled to a fluid source 172 that circulates a temperature regulating fluid through the conduits 168, 170. The embedded thermal isolator 174 may be disposed between the conduits 168, 170 in one embodiment. The heating elements 176 are regulated by a heater power source 178. The conduits 168, 170 and heating elements 176 may be utilized to control the temperature of the thermally conductive base 164, thereby heating and/or cooling the electrostatic puck 166 and a substrate (e.g., a wafer) 144 being processed. The temperature of the electrostatic puck 166 and the thermally conductive base 164 may be monitored using a plurality of temperature sensors 190, 192, which may be monitored using a controller 195.

The electrostatic puck 166 may further include multiple gas passages such as grooves, mesas and other surface features that may be formed in an upper surface of the electrostatic puck 166. The gas passages may be fluidly coupled to a source of a heat transfer (or backside) gas such as He via holes drilled in the electrostatic puck 166. In operation, the backside gas may be provided at controlled pressure into the gas passages to enhance the heat transfer between the electrostatic puck 166 and the substrate 144.

The electrostatic puck 166 includes at least one clamping electrode 180 controlled by a chucking power source 182. The at least one clamping electrode 180 (or other electrode disposed in the electrostatic puck 166 or conductive base 164) may further be coupled to one or more RF power sources 184, 186 through a matching circuit 188 for maintaining a plasma formed from process and/or other gases within the processing chamber 100. The RF power sources 184, 186 are generally capable of producing RF signal having a frequency from about 50 kHz to about 3 GHz and a power of up to about 10,000 Watts.

FIG. 2 is a flow chart showing a process 200 for manufacturing a solid sintered ceramic article, in accordance with one embodiment of the present invention. At block 255, ceramic powders that are to be used to form the ceramic article are selected. Quantities of the selected ceramic powders are also selected.

In one embodiment, the selected ceramic powders include Y₂O₃, Er₂O₃, and one or more additional rare earth oxides that will form a phase with the Y₂O₃ and the Er₂O₃. The additional rare earth oxides should also be erosion resistant and have a high density (low porosity). Examples of the additional rare earth oxides that may be used include ZrO₂ and Gd₂O₃. Non-rare earth oxides can also be used such as Al₂O₃ & SiO₂. In one embodiment, the ceramic powders include Y₂O₃ at a concentration of approximately 30 molar % (mol %) to approximately 60 molar %, Er₂O₃ at a concentration of approximately 20 molar % to approximately 60 molar %, and at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 0 molar % to approximately 30 molar %. In one embodiment, the selected ceramic powders include Y₂O₃ at a concentration of approximately 30-60 molar %, Er₂O₃ at a concentration of approximately 20-55 molar %, and one or more of ZrO₂ at a concentration of up to 20 molar %, Gd₂O₃ at a concentration of up to 20 molar %, and SiO₂ at a concentration of up to 30 molar %.

One specific mixture of ceramic powders that may be used (termed example 1++) includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 35 molar %, Gd₂O₃ at a concentration of approximately 5 molar %, and SiO₂ at a concentration of approximately 15 molar %. Another specific mixture of ceramic powders that may be used (termed example 2++) includes Y₂O₃ at a concentration of approximately 45 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 35 molar %, Gd₂O₃ at a concentration of approximately 10 molar %, and SiO₂ at a concentration of approximately 5 molar %. Another specific mixture of ceramic powders that may be used (termed example 3++) includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 40 molar %, Gd₂O₃ at a concentration of approximately 7 molar %, and SiO₂ at a concentration of approximately 8 molar %. Another specific mixture of ceramic powders that may be used (termed example 4++) includes Y₂O₃ at a concentration of approximately 37 molar %, ZrO₂ at a concentration of approximately 8 molar %, and Er₂O₃ at a concentration of approximately 55 molar %. Another specific mixture of ceramic powders that may be used (termed example 5++) includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 10 molar %, Er₂O₃ at a concentration of approximately 30 molar %, and Gd₂O₃ at a concentration of approximately 20 molar %.

In one embodiment, the selected ceramic powders include 40-60 mol % of Y₂O₃, 30-50 mol % of ZrO₂, and 10-20 mol % of Al₂O₃. In another embodiment, the selected ceramic powders include 40-50 mol % of Y₂O₃, 20-40 mol % of ZrO₂, and 20-40 mol % of Al₂O₃. In another embodiment, the selected ceramic powders include 70-90 mol % of Y₂O₃, 0-20 mol % of ZrO₂, and 10-20 mol % of Al₂O₃. In another embodiment, the selected ceramic powders include 60-80 mol % of Y₂O₃, 0-10 mol % of ZrO₂, and 20-40 mol % of Al₂O₃. In another embodiment, the selected ceramic powders include 40-60 mol % of Y₂O₃, 0-20 mol % of ZrO₂, and 30-40 mol % of Al₂O₃. In another embodiment, the selected ceramic powders include 40-100 mol % of Y₂O₃, 0-60 mol % of ZrO₂, and 0-5 mol % of Al₂O₃.

In one embodiment, the selected ceramic powders include 40-100 mol % of Y₂O₃, 0-60 mol % of ZrO₂, and 0-5 mol % of Al₂O₃. In a first example (termed example 1+), the selected ceramic powders include 73-74 mol % of Y₂O₃ and 26-27 mol % of ZrO₂. In a second example (termed example 2+), the selected ceramic powders include 71-72 mol % of Y₂O₃, 26-27 mol % of ZrO₂, and 1-2 mol % of Al₂O₃. In a third example (termed example 3+), the selected ceramic powders include 64-65 mol % of Y₂O₃ and 35-36 mol % of ZrO₂. In a fourth example (termed example 4+), the selected ceramic powders include 63-64 mol % of Y₂O₃, 35-36 mol % of ZrO₂, and 1-2 mol % of Al₂O₃. In a fifth example (termed example 5+), the selected ceramic powders include 57-58 mol % of Y₂O₃, 42-43 mol % of ZrO₂. In a sixth example (termed example 6+), the selected ceramic powders include 52-53 mol % of Y₂O₃, 47-48 mol % of ZrO₂.

Any of the aforementioned sintered solids may include trace amounts of other materials such as ZrO₂, Al₂O₃, SiO₂, B₂O₃, Er₂O₃, Nd₂O₃, Nb₂O₅, CeO₂, Sm₂O₃, Yb₂O₃, or other oxides.

At block 260, the selected ceramic powders are mixed. In one embodiment, the selected powders are mixed with water, a binder and a deflocculant to form a slurry. In one embodiment, the ceramic powders are combined into a granular powder by spray drying.

At block 265, a green body (an unsintered ceramic article) is formed from the mixed powders (e.g., from the slurry formed from a mixture of the selected ceramic powders). The green body can be formed using techniques including, but not limited to, slip casting, tape casting, cold isostatic pressing, unidirectional mechanical pressing, injection molding, and extrusion. For example, the slurry may be spray dried, placed into a mold, and pressed to form the green body in one embodiment.

At block 270, the green body is sintered. Sintering the green body may include heating the green body to a high temperature that is below the melting point of any of the constituent rare earth oxides in the green body. For example, if the green body includes Y₂O₃, Er₂O₃, ZrO₂, Gd₂O₃ or SiO₂, then the green body may be heated to any point below the melting points of Y₂O₃, Er₂O₃, ZrO₂, Gd₂O₃ and SiO₂. In one embodiment, the sintering is preceded by heating the green body to a low temperature to burn off a binder that was used in the formation of the green body. The green bodies can be sintered at 1500-2100° C. for a time of 3-30 hours (hr).

The sintering process produces a solid sintered ceramic article that includes at least one solid solution made up of the various constituent ceramic materials in a single phase. For example, in one embodiment, the solid sintered ceramic article includes a solid solution that includes Y₂O₃ at a concentration of approximately 30 molar % to approximately 60 molar %, Er₂O₃ at a concentration of approximately 20 molar % to approximately 50 molar %, and at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 0 molar % to approximately 30 molar %.

In various embodiments, the solid sintered ceramic article may be used for different chamber components of a plasma etch reactor. Depending on the particular chamber component that is being produced, the green body may have different shapes. For example, if the ultimate chamber component is to be a process kit ring, then the green body may be in the shape of a ring. If the chamber component is to be an electrostatic puck for an electrostatic chuck, then the green body may be in the shape of a disc. The green body may also have other shapes depending on the chamber component that is to be produced.

The sintering process typically changes the size of the ceramic article by an uncontrolled amount. Due at least in part to this change in size, the ceramic article is typically machined after the sintering process is completed at block 275. The machining may include surface grinding and/or polishing the ceramic article, drilling holes in the ceramic article, cutting and/or shaping the ceramic article, grinding the ceramic article, polishing the ceramic article (e.g., using chemical mechanical planarization (CMP), flame polishing, or other polishing techniques), roughening the ceramic article (e.g., by bead blasting), forming mesas on the ceramic article, and so forth.

The ceramic article may be machined into a configuration that is appropriate for a particular application. Prior to machining, the ceramic article may have a rough shape and size appropriate for a particular purpose (e.g., to be used as a lid in a plasma etcher). However, the machining may be performed to precisely control size, shape, dimensions, hole sizes, and so forth of the ceramic article.

Depending on the particular chamber component that is to be produced, additional processing operations may additionally be performed. In one embodiment, the additional processing operations include bonding the solid sintered ceramic article to a metal body (block 280). In some instances, in which the solid sintered ceramic article is both machined and bonded to a metal body, the machining may be performed first, followed by the bonding. In other instances, the solid sintered ceramic article may first be bonded to a metal body, and may then be machined. In other embodiments, some machining is performed both before and after the bonding. Additionally, in some embodiments the solid sintered ceramic article may be bonded to another ceramic article.

In a first example, the ceramic article is to be used for a showerhead. In such an embodiment, many holes may be drilled into the ceramic article, and the ceramic article may be bonded to an aluminum gas distribution plate. In a second example, the ceramic article is used for an electrostatic chuck. In such an embodiment, helium pin holes are drilled into the ceramic article (e.g., by laser drilling), and the ceramic article may be bonded by a silicone bond to an aluminum base plate. In another example, the ceramic article is a ceramic lid. Since the ceramic lid has a large surface area, the ceramic lid formed from the new sintered ceramic material may have a high structural strength to prevent cracking or buckling during processing (e.g., when a vacuum is applied to a process chamber of the plasma etch reactor). In other examples, a nozzle, a process kit ring, or other chamber component is formed.

FIG. 3 is a chart showing sputter resistance of various solid sintered ceramic articles to a plasma generated under a bias power of 2200 Watts, in accordance with embodiments of the present invention. The chart shows a sputter erosion rate of between 0.10 and 0.15 nanometer per radiofrequency hour (nm/RFhr) for a first example solid sintered ceramic article (example 1+) composed of 73.13 molar % Y₂O₃ and 26.87 molar % ZrO₂. The chart shows a sputter erosion rate of between 0.15 and 0.20 nm/RFhr for a fourth example solid sintered ceramic article (example 4+) composed of 63.56 molar % Y₂O₃, 35.03 molar % ZrO₂, and 1.41 molar % Al₂O₃. The chart shows a sputter erosion rate of between 0.15 and 0.20 nm/RFhr for a second example solid sintered ceramic article (example 2+) composed of 71.96 molar % Y₂O₃, 26.44 molar % ZrO₂, and 1.60 molar % Al₂O₃. The chart shows a sputter erosion rate of between 0.20 and 0.25 nm/RFhr for a third example solid sintered ceramic article (example 3+) composed of 64.46 molar % Y₂O₃ and 35.54 molar % ZrO₂. The chart shows a sputter erosion rate of between 0.25 and 0.30 nm/RFhr for a sixth example solid sintered ceramic article (example 6+) composed of 52.12 molar % Y₂O₃ and 47.88 molar % ZrO₂. The chart shows a sputter erosion rate of between 0.30 and 0.35 nm/RFhr for a fifth example solid sintered ceramic article (example 5+) composed of 57.64 molar % Y₂O₃ and 42.36 molar % ZrO₂. The chart additionally shows sputter erosion resistance rates for solid sintered ceramics of Er₂O₃, Y₂O₃, Gd₂O₃, Er₃Al₅O₁₂ (EAG), 99.8% Al₂O₃, 92% Al₂O₃ and a comparison compound ceramic including 63 mol % Y₂O₃, 14 mol % Al₂O₃, and 23 mol % ZrO₂ for comparison.

FIG. 4 is an additional chart showing erosion resistance of various solid sintered ceramic articles to a plasma generated using an N₂/H₂ chemistry, in accordance with embodiments of the present invention. The chart shows an erosion rate of about 10 nm/RFhr for the first example solid sintered ceramic article composed of 73.13 molar % Y₂O₃ and 26.87 molar % ZrO₂. The chart shows an erosion rate of just over 10 nm/RFhr for the third example solid sintered ceramic article composed of 64.46 molar % Y₂O₃ and 35.54 molar % ZrO₂. The chart shows an erosion rate of just over 10 nm/RFhr for the fourth example solid sintered ceramic article composed of 63.56 molar % Y₂O₃, 35.03 molar % ZrO₂, and 1.41 molar % Al₂O₃. The chart shows an erosion rate of under 15 nm/RFhr for the second example solid sintered ceramic article composed of 71.96 molar % Y₂O₃, 26.44 molar % ZrO₂, and 1.60 molar % Al₂O₃. The chart additionally shows erosion rates for solid sintered ceramics of Y₂O₃, quartz and HPM for comparison.

FIG. 5 is yet another chart showing erosion resistance of various solid sintered ceramic articles to a plasma generated using an CHF₄/CF₄ chemistry, in accordance with embodiments of the present invention. The chart shows erosion rates of just over 0.05 nm/RFhr for the first example solid sintered ceramic article (example 1+), second example solid sintered ceramic article (example 2+), sixth example solid sintered ceramic article (example 6+), and third example solid sintered ceramic article (example 3+) defined with reference to FIG. 3. The chart additionally shows erosion rates of just under 0.75 nm/RFhr for the fifth example solid sintered ceramic article (example 5+) and the fourth example solid sintered ceramic article (example 4+) defined with reference to FIG. 3. The chart additionally shows erosion rates for solid sintered ceramics of Er₂O₃, Y₂O₃, Gd₂O₃, EAG, 99.8% Al₂O₃, 92% Al₂O₃ and the comparison compound ceramic for comparison.

FIG. 6A is a chart showing erosion resistance of various solid sintered ceramic articles to a plasma generated using an N₂/H₂ chemistry, in accordance with embodiments of the present invention. The chart shows an erosion rate of under 15 nm/RFhr for yttria, for the example 4++ ceramic article, and for the example 5++ ceramic article. The chart also shows an erosion rate of just under 20 nm/RFhr for silicon and an erosion rate of over 20 nm/RFhr for the comparison compound ceramic. The example 4++ ceramic includes Y₂O₃ at a concentration of approximately 37 molar %, ZrO₂ at a concentration of approximately 8 molar %, and Er₂O₃ at a concentration of approximately 55 molar %. The example 5++ ceramic includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 10 molar %, Er₂O₃ at a concentration of approximately 30 molar %, and Gd₂O₃ at a concentration of approximately 20 molar %.

FIG. 6B is a chart showing pre-etch and post-etch roughness for solid sintered (bulk) yttria, example 4++, example 5++, silicon and the comparison compound ceramic. As shown, example 4++ and example 5++ solid sintered ceramics show minimum erosion rate and example 4++ shows minimal roughness change.

TABLE 1 Liquid particle count (LPC) for conductor lid in particles per square centimeter (p/cm²) Material >=.2 μm >=.3 μm >=.5 μm >=1 μm >=2 μm Compound 24,875 7,417 3,053 772 145 Ceramic Lid Example 1+ 21,706 6,531 1,926 719 165

Table 1 shows particle defects measured post cleaning of a conductor lid made out of a comparison compound ceramic & the first example ceramic material (example 1+). The first example ceramic material consists of Y₂O₃ at a concentration of 73.13 molar % and ZrO₂ at a concentration of 26.87 molar %. The particle contamination may be measured by performing a liquid particle count (LPC). Each column in the table represents a number of particles that are at least a particular size.

TABLE 2A metal contamination in 10¹⁰ atoms/cm² Material Ca Cr Cu Fe Mg Mn Compound <70 <20 <10 40 <50 <5 Ceramic Example 1+ <70 <20 <10 26 <50 <5

TABLE 2B metal contamination in 10¹⁰ atoms/cm² Material Ni K Na Ti Zn Compound <10 <50 <50 <20 <20 Ceramic Example 1+ <10 <50 <50 <20 <20

Tables 2A and 2B show metal contamination on a wafer processed using a solid sintered ceramic lid of the comparison compound ceramic and the first example ceramic material. Metal contamination may be measured by inductively coupled plasma mass spectroscopy (ICPMS). Each column in the table represents a different metal contaminant. Different formulations of solid sintered ceramic articles described in embodiments herein have different on-wafer metal contamination levels depending on the compositions of those solid sintered ceramic articles. Therefore, based on different on-wafer metal contamination specifications of manufacturers, different formulations can be chosen to manufacture the corresponding chamber components.

TABLE 3 mechanical properties of example solid sintered ceramic articles Elastic Bulk Water Hardness Modulus Density Absorption Material (GPa) (GPa) (g/cm³) (%) Y₂O₃ 9.94 205 4.55 N/A Comparison 13.28 225 4.9 N/A Compound Ceramic Example 1+ 13.27 232 N/A N/A Example 1++ N/A N/A 6.39 0.035 Example 2++ N/A N/A 6.52 0.030 Example 3++ N/A N/A 6.64 0.032 Example 4++ N/A N/A 6.79 0.023

Table 3 shows mechanical properties of the first example (example 1+) solid sintered ceramic article defined with reference to FIG. 2, as well as additional example solid sintered ceramic articles example 1++, example 2++, example 3++, and example 4++ in comparison to mechanical properties of the comparison compound and Y₂O₃ solid sintered ceramic articles.

The preceding description sets forth numerous specific details such as examples of specific systems, components, methods, and so forth, in order to provide a good understanding of several embodiments of the present invention. It will be apparent to one skilled in the art, however, that at least some embodiments of the present invention may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present invention. Thus, the specific details set forth are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present invention.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.”

Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operation may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be in an intermittent and/or alternating manner.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 

What is claimed is:
 1. An article comprising: a plasma resistant ceramic material comprising at least one solid solution, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 30 molar % to approximately 60 molar %, Er₂O₃ at a concentration of approximately 20 molar % to approximately 60 molar %, and at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 1 molar % to approximately 30 molar %.
 2. The article of claim 1, wherein the article comprises a chamber component for a plasma etch reactor, the chamber component being selected from a group consisting of an electrostatic chuck, a lid, a nozzle, a gas distribution plate, a shower head, an electrostatic chuck component, and a processing kit ring.
 3. The article of claim 1, wherein the at least one solid solution comprises ZrO₂ at a concentration of up to 20 molar %, Gd₂O₃ at a concentration of up to 10 molar %, and SiO₂ at a concentration of up to 30 molar %.
 4. The article of claim 1, wherein the article is a solid sintered ceramic article.
 5. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 35 molar %, Gd₂O₃ at a concentration of approximately 5 molar %, and SiO₂ at a concentration of approximately 15 molar %.
 6. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 45 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 35 molar %, Gd₂O₃ at a concentration of approximately 10 molar %, and SiO₂ at a concentration of approximately 5 molar %.
 7. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at a concentration of approximately 40 molar %, Gd₂O₃ at a concentration of approximately 7 molar %, and SiO₂ at a concentration of approximately 8 molar %.
 8. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 37 molar %, ZrO₂ at a concentration of approximately 8 molar %, and Er₂O₃ at a concentration of approximately 55 molar %.
 9. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at a concentration of approximately 10 molar %, Er₂O₃ at a concentration of approximately 30 molar %, and Gd₂O₃ at a concentration of approximately 20 molar %.
 10. The article of claim 1, wherein the at least one solid solution comprises at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 5 molar % to approximately 30molar %.
 11. The article of claim 1, wherein the at least one solid solution comprises ZrO₂ at a concentration of 1-20 molar %.
 12. The article of claim 1, wherein the at least one solid solution comprises Gd₂O₃ at a concentration of 1-10 molar %.
 13. The article of claim 1, wherein the at least one solid solution comprises SiO₂ at a concentration of 1-30 molar %.
 14. The article of claim 1, wherein the at least one solid solution comprises Y₂O₃ at a concentration of approximately 37-45 molar %.
 15. The article of claim 1, wherein the at least one solid solution comprises ZrO₂ at a concentration of approximately 5-10 molar %.
 16. The article of claim 1, wherein the at least one solid solution comprises Er₂O₃ at a concentration of approximately 30-55 molar %.
 17. The article of claim 1, wherein the at least one solid solution comprises Gd₂O₃ at a concentration of approximately 5-20 molar %.
 18. The article of claim 1, wherein the at least one solid solution comprises SiO₂ at a concentration of approximately 5-15 molar %. 